In case you haven’t heard, butter is the new cream when it comes to your morning cup of joe. Called Bulletproof coffee, the trendy “health” drink blends a cup of black coffee with 1 to 2 tablespoons of unsalted, grass-fed butter and 1 to 2 tablespoons of something called medium-chain triglyceride (MCT) oil, a type of easily digested fat.

The man behind the popular coffee concoction: Dave Asprey, a tech entrepreneur who claims the 450-plus-calorie brew suppresses hunger, promotes weight loss, and improves energy and performance. He credits Bulletproof coffee for helping him drop 100-plus pounds, plus helping him get more sleep and boosting his brainpower. (Coffee is one of 5 Everyday Drinks You Didn't Know Could Burn Fat.)

Drink devotees include Silicon Valley execs, NBA players, pro surfer Laird Hamilton, and actress Shailene Woodley—and the buzz isn’t likely to disappear soon. Asprey now sells a variety of Bulletproof-branded products and is currently building a stand-alone Bulletproof coffee shop in Santa Monica, CA. In addition to selling the fat-packed coffee, the café is rumored to be offering a a host of wellness amenities, from lights that complement your circadian rhythms to optional liquid collagen shots that promise to make your skin look younger.

Are Any of These Claims Legit?“Fat is more satiating than nothing, so if you add it to your morning cup, you may feel full longer,” says Bell. “However, turning your 80-calorie cup of coffee into an 400-plus-calorie mug is unlikely to promote weight loss given that its ingredients—coffee, butter and oils—have not been shown to promote weight loss independently or when stirred together. Rather than refer to science here, I’d like to consider it logically—without exercise, is anyone out there losing weight by eating more calories?”

Is There Anything Healthy About Bulletproof Coffee?“While caffeine-containing beverages, like coffee and tea, do have health benefits—antioxidants, enhanced cognitive function, mental acuity, and even a lower risk of total mortality—it’s hard to call Bulletproof coffee ‘healthy,’" says Bell. “We need to eat fat for our body to function properly—especially the essential fatty acids (polyunsaturated fats) found in fish, vegetable oils, nuts and seeds—but adding it to our coffee doesn’t provide any additional health benefits.”

Are There Any Health Risks?“Clinical studies have shown that for many individuals, eating too much saturated fat can contribute to high LDL-cholesterol,” says Bell. “If you fall into that category, you may not want to add butter to a drink that you were satisfied with already.”

Bottom line: if you’re going to drink it, do it for one reason only—because you think it tastes good.